This invention relates generally to humidifiers, and more particularly, control of evaporation in a humidifier used in conjunction with a furnace or heating system and connected to the plumbing system of a building. Humidifiers of this type typically use an air circulation arrangement to move air across a water-soaked evaporative pad. The humidifier is associated with the furnace or heating system so that the humidifier moist air can be combined with the warm, generally dry, heated air and distributed through a building.
Humidifiers generally characterized by a housing having an evaporative water panel constructed of slit and expanded non-wicking paper, removably disposed in a reservoir at the bottom thereof. The housing also has a mechanical float valve which is connected to a water supply of a heated building. A water feed tube is connected to the mechanical float valve for supplying water to a distributor from which water flows by gravity down through the water panel. Air is forced through the water panel and the air evaporates water on the water panel, so that humidified air is delivered to the building.
Such humidifiers typically employ a device such as a humidistat, for establishing predetermined humidity set point and reading humidity levels in the building. The humidistat is connected in a circuit with a pump and operates, in the presence of low humidity, to automatically deliver water from a lower reservoir to the top of the water panel and downwardly therethrough. Some of the water evaporates from the water panel and is air blown to provide humidity to the building. The remainder of the water collects in the reservoir at the bottom of the water panel. As the reservoir level drops due to loss of evaporated water, the float valve opens to allow water in from supply and maintains reservoir level. The pump recirculates water from the reservoir over the non-wicking water panel. This cycle continues as long as the humidistat reads low humidity. Once the humidity set point is reached, the circuit is opened and water flow ceases.
There also exist drum-type humidifiers wherein a motor and gear system is used to rotate a drum in a reservoir of standing water.
While such designs generally provide the desired humidification, there arises problems in the cost, noise, maintenance, electrical power needs and reliability associated therewith. Another problem with these designs is that the reservoir remains filled no matter if humidity is needed or not. As a result, there is a possibility of undesirable bacteria, algae, fungus, mold, etc.
Accordingly, it is desirable to provide a humidifier which is responsive to the changing water level in the reservoir. It is also desirable to provide a humidifier which is more economical in cost, runs more quietly, requires less maintenance and lessens the electrical power needs.
It is one object of the present invention to provide a humidifier employing a float switch which responds to the water level in the reservoir.
It is also an object of the present invention to provide a humidifier which employs a wicking-type evaporative water panel.
It is a further object of the present invention to provide a humidifier which allows for complete evaporation of water in the reservoir.
It is an additional object of the present invention to provide a humidifier which operates normally without the need for a drain.
Still another object of the present invention is to provide a humidifier which is easier to manufacture and maintain and which is safer to operate.
In one aspect of the invention, a housing is permanently connected to a water supply of a building and includes an evaporative water panel allowing water to flow downwardly and wick upwardly. A circulation device is provided for directing air from the building to the water panel. A reservoir is positioned in the housing for supporting the water panel and for holding excess water deposited from the water panel. A water distributor is provided for moving the water from the water supply to the top of the water panel. A water control arrangement is responsive to the water level within the reservoir for automatically controlling the flow of water to the water panel to provide a desired humidity level in the building. The water panel is comprised of a multi-layer, slit and expanded, wicking paper. In the preferred embodiment, the air circulating device includes a blower associated with a furnace, or a fan built integrally into the humidifier and the reservoir includes first and second vertical walls connected to a horizontal base wall. The water control arrangement includes a solenoid valve connected to a water level sensor. The water level sensor is preferably comprised of a float switch having a float member provided with a magnet therein, and a reed switch connected to the solenoid valve. The float member and magnet are positioned above the horizontal base wall of the reservoir, and the reed switch is aligned with the magnet and positioned below the reservoir, isolated from any water contact therewith. In the preferred embodiment, the reservoir includes a tubular chamber and the float member is a ball-shaped float.
The invention also contemplates various other methods for movably mounting the float member. In one embodiment the reservoir includes a post having one end of the hinge slidably attached thereto and another end of the hinge attached to the float member. In another alternative embodiment, the reservoir includes a post having one end of a solid folding hinge attached thereto and the other end of the solid folding hinge attached to the float member. In yet another alternative embodiment, the reservoir includes a set of posts upon which the float member is slidably mounted. In still another alternative embodiment, the reservoir includes a post provided with a pivoted edge having one end of a float arm pivotally attached. thereto and another end of the float arm attached to the float member. In still another alternative embodiment, the reservoir includes a horizontal ledge having one end of a flexible hinge attached thereto and another end of the flexible hinge attached to the float member.
The water distributor is a tube extending from the solenoid valve to an outlet nozzle and a weir-type distributor trough which is positioned over the water panel. The water distributor may also take the form of a feed tube extending from the solenoid valve to an outlet manifold positioned over the water panel. An overflow tube is molded directly to the side of the reservoir for receiving any water which overflows the reservoir. The humidifier typically includes a humidistat for establishing a desired humidity level.
In another aspect of the invention, the humidifier has a device for controlling the flow of water to an evaporative water panel positioned in a reservoir and allows water to flow downwardly and wick upwardly. The humidifier also has a humidistat for establishing a desired humidity level and an operative circulating means for directing air through the water panel. The humidifier includes a water level sensor which is associated with the reservoir and which is responsive to the water level therein to alternatively open and close a circuit to control the flow of water to the water panel. With this construction, when the water level in the reservoir is low, the circuit is closed to deliver water to the water panel such that some water evaporates from the water panel and the remainder collects in the reservoir. A rising water level in the reservoir causes the sensor to open the circuit, stopping water delivery, humidification continuing as water wicks upwardly through the water panel. The falling water level in the reservoir causes the sensor to close the circuit, delivering further water to the panel, the reservoir eventually drying out once the desired humidity is reached. The humidistat forces the circuit open when the desired humidity level is reached so as to prevent the water cycling on and off indefinitely. Stoppage of the circulating means will have the same effect.
Various other features, objects, and advantages of the invention will be made apparent from the following description taken together with the drawings.